From: Arnd Bergmann <arnd@arndb.de>
To: Amit Ben Shahar <amit.bens@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Why is the 'loff_t *offset' parameter in the file_operations' read function a pointer?
Date: Tue, 26 Apr 2011 14:37:53 +0200 [thread overview]
Message-ID: <201104261437.53925.arnd@arndb.de> (raw)
In-Reply-To: <BANLkTimaJFFCCQOA6=G4i95PsJK_S2bf9Q@mail.gmail.com>
On Tuesday 26 April 2011, Amit Ben Shahar wrote:
> (if i'm off topic or should look elsewhere i apologize - couldn't find
> information anywhere)
> I am coding a kernel module and implementing a file's operations, the
> read operation received an loff_t *offset parameter, why is this a
> pointer? is it in userspace?
The read function must update the offset independent of the return value.
See simple_read_from_buffer() as an example.
Arnd
next prev parent reply other threads:[~2011-04-26 12:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-26 11:58 Why is the 'loff_t *offset' parameter in the file_operations' read function a pointer? Amit Ben Shahar
2011-04-26 12:30 ` Jiri Slaby
2011-04-26 12:37 ` Arnd Bergmann [this message]
2011-04-26 12:55 ` Amit Ben Shahar
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